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Salvimar Predathor Vuoto 100

vaggelakis

Well-Known Member
Jun 19, 2008
14
6
93
Hello everyone, I just have a question concerning the salvimar vuoto. Can you load the gun underwater without even a bit of water entering the barrel, or you have to keep the muzzle out of the water while loading like the 'older' dry barrel pneumatic spearguns?
 

popgun pete

Well-Known Member
Jul 30, 2008
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You can load it while submerged. The gun relies on a small amount of water to lubricate the barrel in front of the advancing piston when the gun shoots. When you insert the spear tail underwater excess water pushes out through the vacuum seal, that is why the seal has that nozzle shape.
 

vaggelakis

Well-Known Member
Jun 19, 2008
14
6
93
Thanks for the fast response Pete. So, while loading the gun underwater the muzzle gasket stops 100% of water from entering the barrel, OR a small amount of water enters the barrel and the piston pushes it out everytime you shoot?
 

popgun pete

Well-Known Member
Jul 30, 2008
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The water that goes down the barrel is the small amount sitting in the muzzle once the spear tail is inserted. This illustration that was done some time ago shows the water in blue. As the spear is pushed down the inner barrel no extra water can get in as it is kept out by the seal created by the rim of the rubber nozzle running on the shaft, so a partial vacuum is created in the inner barrel. The water inside probably converts to a vapour, but there is no way to actually see it.
salvimar muzzle with water inside.jpg

During the shot the water vapour returns to a liquid and reforms the volume that was there before loading started and when the spear detaches from the piston the spear leaves the muzzle and water rushes in to fill the space left in the muzzle by the departing spear tail. If some water does leak in then the muzzle seal will let it out by stretching the nozzle and expanding it enough for the water to escape, however with the seal and spear surface in good condition very little extra water will get in.
 
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Stamatis

Active Member
Aug 29, 2017
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Thanks for the fast response Pete. So, while loading the gun underwater the muzzle gasket stops 100% of water from entering the barrel, OR a small amount of water enters the barrel and the piston pushes it out everytime you shoot?
What Pete said is of course accurate as always, still I'd like to stress out that failing to insert the shaft without any water into the muzzle, shall destroy the muzzle gasket eventually.
With this opportunity, I'd like ot report that I haven't replaced the gasket yet since I bought the gun (it's been a few years now) so apparently it takes a considerable number of shots before the gasket starts to deteriorate.;)
 

stefpix

Member
Aug 15, 2015
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What Pete said is of course accurate as always, still I'd like to stress out that failing to insert the shaft without any water into the muzzle, shall destroy the muzzle gasket eventually.
With this opportunity, I'd like ot report that I haven't replaced the gasket yet since I bought the gun (it's been a few years now) so apparently it takes a considerable number of shots before the gasket starts to deteriorate.;)
I had to replace he gasket after a year on my vuoto 55. I went spearfishing in April and missed so many shots. I shot a blackfish (tautog) in the skull and the spear tip barely exited. There was a cut on the gasket. I replaced it, next time I shot a blackfish in the skull the whole shaft went through. It may be worth replacing the gasket after the winter break, no matter of what. I think the rubber wears out and it is pretty soft.
 

Stamatis

Active Member
Aug 29, 2017
111
33
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I had to replace he gasket after a year on my vuoto 55. I went spearfishing in April and missed so many shots. I shot a blackfish (tautog) in the skull and the spear tip barely exited. There was a cut on the gasket. I replaced it, next time I shot a blackfish in the skull the whole shaft went through. It may be worth replacing the gasket after the winter break, no matter of what. I think the rubber wears out and it is pretty soft.
Well, I guess it depends. The 100 is meant for ambush, and as such, the number of shots is reduced to minimum by design.
 

popgun pete

Well-Known Member
Jul 30, 2008
4,145
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It is worth buying one of those jewellers’ loupes that you can use to periodically check the seal's leading edge. Check out a new seal and then see what a used one looks like. The edges only chip and wear if they are exposed to dry friction or the spear has surface imperfections that cut tiny pieces of rubber away. Although spears look smooth they have a micro texture, but with any lubrication this is not enough to tear up the sealing edge. Rubber deteriorates with time and heat, so best to not to leave your gun cooking in the sunlight. Storing rubber goods near electric motors can deteriorate rubber faster than normal, so don't store your gun in proximity to washing machines or clothes driers that are frequently in use.
loupes.jpg

 
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vaggelakis

Well-Known Member
Jun 19, 2008
14
6
93
@popgun pete thanks for the response once again, that is exactly what I wanted to know.
@Stamatis you still have the original muzzle gasket after 4 years, impressive. I thought it would last, maximum, a year.

I've ordered my first pneumatic speargun, a vuoto 85, and Im looking forward to test it.
 
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Stamatis

Active Member
Aug 29, 2017
111
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@popgun pete thanks for the response once again, that is exactly what I wanted to know.
@Stamatis you still have the original muzzle gasket after 4 years, impressive. I thought it would last, maximum, a year.

I've ordered my first pneumatic speargun, a vuoto 85, and Im looking forward to test it.
You're gonna love it, it is guaranteed!

BTW it just came to me that a good reason for fast gasket deterioration is debries (as it is mentioned earlier in this thread). If one is not careful, they might insert debris accidentaly inside the muzzle and eventually destroy the gasket
 

vaggelakis

Well-Known Member
Jun 19, 2008
14
6
93
I've heard that keeping the gasket in excellent condition is the most importand thing for ths particular speargun (clean water after use, silicon grease, avoid sand in the muzzle).
Concering the pressure, the manufacturer recomends 20-22 bar, which seems sufficient from the videos on youtube, but what is the maximum pressure that you can use it, without any modifications required.
 

Stamatis

Active Member
Aug 29, 2017
111
33
43
45
I've heard that keeping the gasket in excellent condition is the most importand thing for ths particular speargun (clean water after use, silicon grease, avoid sand in the muzzle).
Concering the pressure, the manufacturer recomends 20-22 bar, which seems sufficient from the videos on youtube, but what is the maximum pressure that you can use it, without any modifications required.
Well, you can go over that, but good luck loading the gun! It's hard as it is!
 

popgun pete

Well-Known Member
Jul 30, 2008
4,145
1,115
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I note the "Vuoto" muzzles were made a little longer a year or so back and never thought too much about it at the time. However on wet barrel guns for many years the muzzle front nut aperture could be sized to allow only the correct shaft size to be used in terms of the tail stop diameter and thus served to hold the shaft in direct alignment before you pushed on it so that the shaft tail tip was aligned perfectly parallel to the piston axis. This made sure that the shaft was not shoved in at an angle, however slight, into the piston. Now on vacuum barrel guns this bore hole in the front nut had to be shortened in length as that space was now taken up by the vacuum seal rubber nozzle. This was not a problem provided the stop ring was already pressed into the muzzle as that helps align the shaft tail in the muzzle (in practice this only happens once the shaft is already in the muzzle). However if it wasn't then the short length of that bore may have allowed a slightly skewed shaft tail presentation that dragged the vacuum seal off-line and damaged the vacuum cuff progressively. It occurs to me that this “new” longer nose may restore that guiding capability by adding a bit more length to the bore hole in the muzzle front nut. My two “Vuoto” guns have the earlier more rounded muzzle nose, so I have never seen the later cone-ended nose to check it out.
Salvimar muzzle comparison.jpg
 
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popgun pete

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Jul 30, 2008
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From the Salvimar catalogs. The new muzzles were shown as spare parts in the 2020 catalog, but only depicted on the guns in the 2021 catalog.
Salvimar Predathor Vuoto muzzle change.jpg
 

popgun pete

Well-Known Member
Jul 30, 2008
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The new muzzles make the rubber seal last longer.
And now you know why. The Russian “Taimen” was the first production gun to use these rubber nozzle type vacuum seals and was designed to control the shaft entry and exit from the muzzle as much as possible in order to extend the life of the “vacuum cuff”. There was good reason for this as for most of its production run the “Taimen” gun had to be totally dismantled to change the cuff, it having to be installed from the muzzle rear. Unscrewing the muzzle from the inner barrel risked damaging a fat cross section “O” ring unique to the gun with the inner barrel nose screw threads cutting it on the way out. This thick “O” ring also had to be squeezed into place in the muzzle by pressing on it from the rear, another reason to dismantle the gun starting from the rear handle end. In recent years the design was changed using a removable front section two piece muzzle in order to easily change the vacuum cuff.

Salvimar could further improve their “Vuoto” gun by plugging the line slide into the muzzle like a socket as the “Taimen” does which ensures shaft alignment into the gun, but they would need better line slides made of metal, preferably alloy which is strong but not too heavy. Their current split tail line slide is not ideal.
Taimen muzzle with polyurethane bush.jpg

Added another diagram, a picture is worth a 1000 words.
tail projection.jpg
 
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